Membrane Filtration Procedure - A sterile absorbent pad is placed at the bottom half of sterile Petri dish using sterile forceps. A suitable broth is poured over the pad so that it is completely saturated with the broth. The Petri dish is closed and kept aside. Touching only the outer side of the holder, the sterile filter holder assembly is opened and the funnel is removed from the top.
A sterile filter is placed on the filter support screen with the grid side up. The funnel assembly is replaced tightly without destroying the membrane. The sample is poured into the funnel wetting the filter. For smaller sample size, 20-30ml of sterile buffer can be poured first to give an even distribution of the sample.
